1. Field of the Invention
The present invention is directed to an improvement in a releasable flexible fabric hook and loop fastener which has strap ends releasably engageable with each other to form a loop.
2. Description of the prior art
Releasable, flexible fabric hook and loop fasteners have been commercially available for many purposes for quite some time. Such hook and loop fasteners form releasable closures having mutually engageable contact surfaces, one of which bears a multiplicity of projecting flexible hooks, typically formed of nylon or other plasticized fabric. The other contact surface bears a flexible, looped pile. The contact surfaces are positionable in juxtaposition in an overlapping relationship, whereupon the hooks become releasably engaged in the pile. Such releasable fasteners have been sold for many years under the registered trademark Velcro and are described, for example, in the following U.S. Pat. Nos. 2,717,437; 3,009,235; 3,241,881; 3,313,511; 3,027,566; 3,338,291; 2,976,914; 3,328,081; 3,485,529; and 3,279,008, as well as many others.
While flexible hook and loop fasteners have been employed in many different applications, one very versatile fastener has a pair of strap ends which extend from a central region that is secured to some base object The strap ends are disengageable from each other and are constructed with hook and loop contact surfaces thereon, of the type described. The free strap ends are adapted for mutually releasable interengagement to cooperatively form a loop when disposed in facing, overlapping arrangement in contact with each other.
Such a loop may be utilized in any number of different ways. For example, the loop may be anchored at an intermediate location between the free ends to some base structure, and the free ends may be utilized to releasably secure articles in position relative to the base structure. Tools may be releasably held on a mounting board or in a tool kit in this manner. Likewise, medical instruments may be removably held against the surface of an instrument kit. Luggage may be held in position within an enclosure in the same fashion. Innumerable other applications exist where the free ends of fabric hook and loop straps are releasably secured together to form an encircling or encompassing loop.
Although fabric hook and loop encircling straps have been used in the foregoing manner for many years, one problem which has persisted has been the inability to quickly separate the straps using only one hand. When strap ends are releasably engaged together, an inwardly facing contact surface on an outermost strap is disposed in contact with an outwardly facing contact surface on an innermost strap. The outer strap overlaps the inner strap throughout an area of mutual contact between the contact surfaces. The resilient hooks are releasably embedded in the loops of the pile, thereby holding the strap ends in overlapping contact with each other to maintain an enclosing loop.
While the force with which the strap ends are held together is quite significant in the aggregate, the strap ends can be separated relatively easily by merely gripping the exposed tip of the outer strap and peeling it back from the inner strap, thereby separating the mutually engaged hooks and loops bit by bit. However, where both the inner and outer strap ends are free and unconstrained, the inner strap will tend to follow the outer strap in the direction in which the outer strap is pulled. Consequently, in many instances the outermost strap will be pulled taut against the location at which the intermediate portion of the loop is anchored to a base structure before separation from the innermost strap occurs. As a result, total separation of the strap ends is not achieved by merely peeling the outer strap. Instead, it is necessary to seize the inner strap and prevent the tip of the inner strap from being carried with the outer strap as the outer strap is peeled back. Total separation of the strap ends is thereby achieved, but only through the use of two hands.
In many situations it is desirable to totally separate the overlapped ends of fabric hook and loop fastener straps quickly while using but a single hand, as the other hand of the user may be occupied with other matters. For example, it is highly desireable for a physician to be able to open the strap ends of a flexible fabric hook and loop fastener using the fingers of a single hand, in order to remove a medical instrument from an instrument case, thereby freeing the physician's other hand. Numerous other situations exist in which it is likewise desirable to quickly and easily separate the interengaged free strap ends of a hook and loop fabric fastener formed into a loop or ring using the fingers of a single hand However, the construction of conventional hook and loop fastener strap ends is such that complete separation cannot be achieved in this manner.